(define (pascal-row row)
  (pascal-iter row row))

(define (pascal-iter row count)
  (pascal-iter row (- count 1)))

(define (pascal-position row col)
  (cond ((and (= row 1) (= col 1)) 1)
        ((and (= row 1) (or (< col 1) (> col 1))) 0)
        (else (+ (pascal-position (- row 1)
                                  (- col 1))
                (pascal-position (- row 1)
                                  col)))))
